【Nanyue Stage Lighting Network】Light, is the life of television art. The safe and reliable dimming system is a powerful guarantee to light the objective world. Any professional dimming system, its power is great, a single bulb is 5kW or even 10kW, and a performance can be used thousands of bulbs. Thus, the total power consumption of a dimming system is staggering. Therefore, the dimming system efficiency and heat dissipation is very important, it is the long-term operation of the dimming system to maintain its reliability key.

Dimming equipment has experienced four generations: the first generation of resistance-type dimmer. The second generation of transformer-type dimming equipment. The third generation is the electromagnetic amplifier type dimming equipment. The fourth generation is SCR dimming equipment. The first generation of the lowest efficiency, the fourth generation of the highest efficiency.

If the dimming system is not efficient, its own power consumption is considerable. Assuming its efficiency is 96% (it seems to be a very good number), when it is to promote a 6kW load, its own power consumption is already:

6 × (100% -96%) = 0.24 kW

Also assume that a dimming cubicle with 60 6kW load, this time, its total power consumption is as high as:

0.24 × 60 = 14.4 kW

Therefore, it is important to improve the efficiency of the dimming system. It not only reduces the temperature rise of the dimming cubicle (because the temperature rise and power consumption are proportional), but also reduces the power consumption, thereby reducing operating costs. At present, the more advanced dimming system using the latest solid-state switch and efficient.

Choke, the efficiency of up to 98% or more, reducing the non-100% dimming current sharp rise caused by the great interference. (Thyristor is to change the conduction angle to adjust the voltage, and its conduction time is only about 1μs or so, this current waveform is actually a very sharp front pulse.

However, even a very efficient dimming system, cooling system performance and design is still very important. Even if the efficiency of 98% to the above example, its own power consumption is still as high as 7.2kW. To such a large power consumption effectively discharged to the system, to keep the system components within a reasonable temperature environment, the cooling system of rational design can not be ignored.

At present, the world's popular cabinet cooling system has three kinds: forced air, forced ventilation and intelligent ventilation.

(1) forced air supply

The cooling system is installed in the bottom of the blower fan, so that fresh air from the bottom of the cabinet into the post-up to speed up the blow, so take away the heat generated by the SCR.

The benefits of this approach is high efficiency, with a small fan can take a lot of heat away. Its drawback is drawn from below the cold air in the upward flow on the way by the SCR power consumption has been heated, so the top of the SCR temperature is much higher than the bottom, resulting in the top of the SCR Of the reliability and life expectancy.

(2) forced ventilation

The system is designed to install the exhaust fan at the top of the cubicle. Through the appropriate process design to make fresh air from the front of each SCR into, and then through the exhaust air to the hot air outside the cabinet.

This approach, through precise design (hydrodynamics) and rigorous process control, achieves approximately the same amount of airflow from top to bottom for each thyristor, thus allowing each thyristor to be in an acceptable Of the temperature range of operation, to ensure the reliability of each SCR. However, this design also has shortcomings, is a larger wind resistance, the need to increase the exhaust fan power, and thus greater noise.

(3) intelligent ventilation

Since the dimming system will rarely be fully loaded in normal operating conditions, the required amount of exhaust air can be reduced relatively. Intelligent ventilation is based on this theory, by detecting the temperature rise inside the closet, and then determine the amount of ventilation in the general operating environment, only low-speed fan operation, the noise is relatively lower, but when the load increases, the fan will be accelerated accordingly. In this way, while retaining the advantages of forced ventilation, while also addressing the shortcomings of high noise.

Finally, it is worth mentioning that, although with a high dimming efficiency and good cooling system, but the dimming system is always a great electrical power system. High temperature and the emergence of arcing and other phenomena can not be completely avoided. Only in the high efficiency and good heat basis, supplemented by the necessary anti-high temperature and fire prevention measures (such as the use of high-temperature fire-retardant line), can guarantee the safety of the entire dimming system.